As the range of therapeutic endolumenal and transgastric treatments available to gastroenterologists and surgeons expands, the tools used to perform such procedures are becoming more complex. Increasingly sophisticated maneuvers demand greater functionality within the limited space offered by the gastrointestinal tract. Consequently, the size of surgical end effectors developed to achieve this functionality will increase, preventing operation through a working channel of an endoscope, which is the traditional approach to endoscopic procedures. Unfortunately, if an instrument is not passed through an endoscope, articulation and control of a distal end of the instrument is difficult if not impossible.
Instruments have been developed that do provide control of tools extending tangential to an endoscope. For example, accessory channels that run along side an endoscope have been developed with steering mechanisms at the distal end for effecting movement of a tool inserted therethrough. While this provides the advantage of articulation independent of a working channel, the size of the tool cannot exceed the diameter of the body lumen, e.g., the esophagus, less the diameter of the endoscope.
Accordingly, there remains a need for methods and devices for delivering end effectors through a body lumen without the size constraints required by a working channel, yet that allows for endoscopic control. There also remains a need for methods and devices for performing multiple surgical procedures using multiple end effectors without the need to exchange the end effectors through the working channel of an endoscope.